Wonder how the planet's flashiest billionaires tell the time? From gem-encrusted masterpieces to amazing feats of horological engineering, feast your eyes on the most pricey wrist and pocket watches in the world.

Boasting luminous Breguet numerals and cased in opulent 18k yellow gold, this Patek Philippe chronograph wristwatch was sold at auction in 2013 for £1.1 million. Adding to the allure, only three examples exist, the most renowned of which once belonged to jazz legend Duke Ellington.

A private museum in Switzerland snapped up this rare oversized pilot's watch at auction in 2009. The one-of-a-kind aviator's timepiece was crafted in 1936 as a unique prototype and features a pioneering large 55mm dial finished in striking black lacquer.

Blancpain's flagship timepiece is encrusted with 480 stunning baguette diamonds totalling 58 carats. The watch rocks an extra-long seven-day power reserve plus it's water-resistant up to 100 meters – not that you'd be likely to go swimming with £1.24 million-worth of bling strapped to your wrist.

Sold at the Geneva outpost of Christie's in 2006, this unassuming-looking timepiece dates from 1925 and is the only Patek Philippe watch designed for a left-hander, a characteristic that adds considerably to its exclusive cachet.

Dubbed 'the secret billionaire's handshake', a cutting-edge Richard Mille watch is regarded as the ultimate stealthy status symbol. This groundbreaking transparent timepiece, which debuted in 2012, was the first wristwatch to feature a case made entirely from sapphire crystal.

The venerable German watchmaker produces just one of these watches a year and only six will be created, hence the hefty price-tag. The 18k rose gold watch seriously impresses with 876 handmade parts and seven complications – a complication is any function on a timepiece that does more than tell the time.

This relatively basic-looking 1944 Patek Philippe model is the third most expensive stainless steel watch ever sold. You may wonder why anybody would spend so much money on a stainless steel timepiece. In fact, stainless steel Patek Philippe watches are super-rare, more scarce than rose gold or platinum.

The most valuable Richard Mille timepiece, this hi-tech see-through watch draws inspiration from the aforementioned RM 56-01, as well as the RM 27-01, which was designed for Spanish tennis pro Rafael Nadal. Launched in 2014, the watch is part of a limited edition of just 10.

Breaking records when it was auctioned in 2007, this 1957 Patek Philippe timepiece was the most expensive watch sold at Christie's at the time. The record didn't last very long however, falling just three years later.

Only one of these 18k rose gold marvels was made and the watch's existence wasn't even publicly acknowledged until it went under the hammer at Christie's Geneva in 2011. Crafted in 1968, the timepiece wows with 37 jewels and a silvered matte dial.

This 18k gold Patek Philippe timepiece showcases the groundbreaking world time or heures universelles system, which was designed and patented in the early 1930s by leading watchmaker Louis Cottier.

The most expensive brand new wristwatch currently on sale and Patek Philippe's most complicated timepiece, the Grandmaster Chime Ref. 6300 is a masterclass in craftsmanship, boasting both grande and petite sonneries or chimes, in addition to 18 different complications.

Created in honour of renowned mathematician Leonardo 'Fibonacci' Pisano, this exquisite white gold pocket watch is inlaid with mother of pearl and finished with an enamelled lotus floral design that fits Pisano's golden ratio.

Patek Philippe's original Grandmaster Chime was launched in 2014 as a limited edition of six. Featuring 20 complications and a total of 1,580 components, the extra-special watch was only made available to a selection of hand-picked Patek Philippe connoisseurs.

The Aeternitas Mega 4 by 'Master of Complications' Franck Muller is the world's second most complicated watch, with 36 complications, 1,483 components and 99 rubies. A wonderfully skillful endeavour, the watch was five years in the making.

A real showstopper, this ostentatious 18k gold Cartier watch, unveiled in 2010, features a bejewelled phoenix with emerald eyes and is literally covered with 3,010 diamonds totalling an impressive 80.13 carats.

Patek Philippe’s very first split-seconds chronograph wristwatch, this groundbreaking timepiece took an incredible 20 years to make and was sold by Sotheby's New York in 2014 for just under £2 million to the Patek Philippe Museum in Switzerland.

Not the most subtle watch in our round-up, this light-reflecting Piaget wristwatch is all about the diamonds, which it certainly doesn't skimp on. A one-of-a-kind work of art, the timepiece is set with 1,211 of the valuable gems.

The only example of a single-button chronograph by Patek Philippe cased in white gold, this super-rare timepiece was sold at auction in 2011. Production of single-button chronograph watches was limited in the 1920s, which explains their scarcity.

This Patek Philippe beauty was put up for auction by rock star Eric Clapton in 2014 and went for £2.5 million. Clapton is an avid collector of haute horlogerie, particularly Patek Philippe and Rolex.

Another Patek Philippe masterpiece, this titanium grand complication watch provided some serious cash for the Monegasque Association against Muscular Dystrophy when it was sold in September 2013 at the Only Watch charity auction in Monaco.

Sold at Geneva's Antiquorum auction house in 2002, this eye-catching Patek Philippe timepiece was created in 1939 and is a complete one-off. The platinum dial features a rotating outer ring inscribed with the names of 24 world cities.

The most expensive wristwatch without complications ever sold at auction, this 1952 Philippe Patek timepiece, which was specially made for collector J.B Champion Jr., features a platinum chronometer, along with solid platinum casing.

More mini planetarium than watch per se, Louis Moinet's out of this world timepiece features four torbillon watches, each of which is set with a space rock, from either the moon, Mars or an asteroid, with a suitably astronomical price tag to match.

This exceedingly fine 18k gold pocket watch by Parisian watchmaker Breguet & Fils was bought by a Mr Garcia of London for 5,000 francs back in 1814. Fast-forward to 2014, and the timepiece was sold for £3.3 million at Christie's in Geneva.

The second most expensive stainless steel watch in the world was sold last year by Phillips auctioneers and made a cool £2.8 million over its estimate of just £693,000. Nicknamed 'the doctor's chronograph', it features a pulsometer scale around the dial.

Beyoncé gifted this jaw-dropping diamond-studded timepiece to her ridiculously lucky husband Jay-Z for his 43rd birthday in 2012. The flagship Hublot watch is covered with 1,282 diamonds totalling more than 100 carats.

The most valuable wristwatch ever sold at Christie's Geneva, this historically important 18k gold Patek Philippe classic was the world's first wristwatch to feature a perpetual calendar, moon phases and a chronograph.

This pocket watch was created to mark Patek Philippe's 150th anniversary in 1989. One of the most complicated watches in the world, with 33 complications, the Calibre 89 features a total of 1,728 components, including a star chart and a thermometer.

Patek Philippe donated this wristwatch to last year's Only Watch charity auction in Monaco. The metallic watch – the most expensive stainless steel timepiece ever sold at auction – was acquired for £5.2 million, making it also the most valuable item ever sold at the charity auction.

Eight years in the making, the breathtaking Vacheron Constantin Ref. 57260 is the world's most complicated pocket watch, with a total of 57 complications and over 2,800 components. Unveiled last year, it is estimated to be worth up to £6.9 million.

Unveiled at last year's prestigious BaselWorld trade show, the 18k white gold Billionaire Watch by Jacob & Co is adorned with 260 carats-worth of brilliant emerald-cut diamonds and features a handcrafted movement comprising 167 components and 19 jewels.

This famous pocket watch, which once belonged to legendary watch collector Henry Graves, was sold at auction in November 2014 for a massive £16.7 million. With 24 complications and 920 components, the 1933 watch is the most complicated timepiece designed without the aid of a computer.

Designed to resemble a flower, this gem-studded Chopard creation is made up of 874 pink, yellow, blue and white diamonds totalling 201 carats. The dazzling timepiece was sold in 2000 for £17.3 million.

Thanks to its exquisite craftsmanship and illustrious history – the timepiece was commissioned in 1783 by Count Hans Axel von Fersen, an alleged lover of Marie Antoinette – this seven-complication Breguet timepiece has been valued at £20.8 million.

All in the best possible taste, Graff's Hallucination wristwatch is worth an eye-watering £38 million, about the same price as a Gulfstream G600 private jet. The 110-carat timepiece is studded with extremely rare coloured diamonds, upping its value.